Parameters will be measured prior to, during, and at the end of the study. Safety will be assessed by physical examinations and clinical laboratory tests. Primary efficacy will be measured by neuropsychologic tests including Alzheimer's Disease Assessment Scale (cognitive subscale), Clinician's Interview Based Assessment of Change (Plus Version). Secondary efficacy will be measured by the CDR-SB, MMSE, and the Alzheimer's Disease Functional Assessment and Change Scale (ADFACS).